Development and analysis of a 50‐year high‐resolution daily gridded precipitation dataset over Spain (Spain02)

Abstract

ABSTRACT:In this paper, we present a new publicly available high-resolution daily precipitation gridded dataset developed for peninsular Spain and the Balearic islands using 2756 quality-controlled stations (this dataset is referred to as Spain02 ). The grid has a regular 0.2°(approx. 20 km) horizontal resolution and spans the period from 1950 to 2003. Different interpolation methods were tested using a cross-validation approach to compare the resulting interpolated values against station data: kriging, angular distance weighting, and thin plane splines. Finally, the grid was produced applying the kriging method in a two-step process. First, the occurrence was interpolated using a binary kriging and, in a second step, the amounts were interpolated by applying ordinary kriging to the occurrence outcomes. This procedure is similar to the interpolation method used to generate the E-OBS gridded data -the state-of-the-art publicly available high-resolution daily dataset for Europe -which was used in this study for comparison purposes. Climatological statistics and extreme value indicators from the resulting grid were compared to those from the 25 km E-OBS dataset using the observed station records as a reference. Spain02 faithfully reproduces climatological features such as annual precipitation occurrence, accumulated amounts and variability, whereas E-OBS has some deficiencies in the southern region. When focusing on upper percentiles and other indicators of extreme precipitation regimes, Spain02 accurately reproduces the amount and spatial distribution of the observed extreme indicators, whereas E-OBS data present serious limitations over Spain due to the sparse data used in this region. As extreme values are more sensitive to interpolation, the dense station coverage of this new data set was crucial to get an accurate reproduction of the extremes.

Scaling precipitation extremes with temperature in the Mediterranean: past climate assessment and projection in anthropogenic scenarios

“…E-OBS has been widely used for regional climate model evaluation (e.g. Lorenz and Jacob 2010;Nikulin et al 2011;Samuelsson et al 2011;Torma et al 2011;Flaounas et al 2013;Stéfanon et al 2014) and has been comprehensively evaluated in the literature (Hofstra et al 2009(Hofstra et al , 2010Kysel and Plavcov 2010;Flaounas et al 2012;Herrera et al 2012). In the E-OBS version 10 used here substantial improvements were realized, especially by increasing the station density (around 2000 for v1 and v2 vs. more than 4200 stations for temperature and more than 7300 for precipitation in v10).…”

Rainfall in Iberian transnational basins: a drier future for the Douro, Tagus and Guadiana?

“…This was produced by merging two datasets, a Portuguese dataset: PT02 (Belo-Pereira et al 2011) and a Spanish dataset: Spain02 (Herrera et al 2012). Both datasets have a resolution of 0.2°× 0.2°(see Fig.…”

Seasonal to yearly assessment of temperature and precipitation trends in the North Western Mediterranean Basin by dynamical downscaling of climate scenarios at high resolution (1971–2050)

“…However, they present non negligible differences over the same region and these uncertainties have to be considered (Gómez-Navarro et al 2012). For this work, Spain02 (SP02) is selected (Herrera et al 2012) due to the high density of the observational network included. SP02 provides daily surface air temperature and accumulated precipitation for Spain over a regular grid of 0.2°resolution.…”